{"product_id":"ds1307-tiny-rtc-i2c-real-time-clock-module-at24c32-eeprom-arduino","title":"DS1307 Tiny RTC I2C Real-Time Clock Module – AT24C32 EEPROM (Arduino)","description":"\u003cstyle\u003e.nznpd{--o:#F57C00;--od:#E65100;--ink:#0F172A;--mut:#5b6573;--line:#E8ECF0;--soft:#F7F8FA;max-width:1120px;margin:0 auto;color:var(--ink);font-family:inherit;line-height:1.6} .nznpd,.nznpd *{box-sizing:border-box} .nznpd p{margin:0;color:var(--mut);font-size:15px;line-height:1.65} .nznpd strong{color:var(--ink)} .nznpd__intro{font-size:16px;color:var(--ink);font-weight:500;line-height:1.6;max-width:none} .nznpd__checks{list-style:none;padding:0;margin:22px 0 0;display:grid;grid-template-columns:repeat(2,1fr);column-gap:26px;row-gap:13px} .nznpd__checks li{display:flex;gap:11px;align-items:flex-start;font-size:15px;color:var(--ink);line-height:1.45} .nznpd__checks li::before{content:\"\\2713\";flex:0 0 auto;width:21px;height:21px;margin-top:1px;border-radius:999px;background:#FFF3E8;color:var(--o);font-size:12px;font-weight:900;line-height:21px;text-align:center} .nznpd__qs{background:linear-gradient(170deg,#FFF9F3,#FFF1E6);border:2px solid #FCE0C6;border-radius:16px;padding:22px} .nznpd__qs h3{margin:0 0 16px;font-size:12px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:var(--od)} .nznpd__steps{list-style:none;counter-reset:s;padding:0;margin:0;display:grid;gap:14px} .nznpd__steps li{display:grid;grid-template-columns:27px 1fr;gap:12px} .nznpd__steps li::before{counter-increment:s;content:counter(s);width:27px;height:27px;border-radius:999px;background:#fff;border:2px solid #FCE0C6;color:var(--od);font-weight:800;font-size:13px;display:flex;align-items:center;justify-content:center} .nznpd__steps strong{display:block;font-size:14px} .nznpd__steps p{font-size:13px;margin-top:2px;line-height:1.45} .nznpd__block{margin-top:36px;padding-top:30px;border-top:1px solid var(--line)} .nznpd__h{margin:0 0 28px;font-size:1.15rem;font-weight:800;letter-spacing:-.02em;color:var(--ink);display:flex;align-items:center;gap:10px} .nznpd__h::before{content:\"\";flex:0 0 auto;width:20px;height:3px;border-radius:2px;background:var(--o)} .nznpd__specs{border:2px solid var(--line);border-radius:12px;overflow:hidden} .nznpd__spec{display:grid;grid-template-columns:minmax(150px,.7fr) 1fr;gap:18px;padding:12px 16px;font-size:14px} .nznpd__spec:nth-child(odd){background:var(--soft)} .nznpd__spec span{color:var(--mut)} .nznpd__spec strong{font-weight:700} .nznpd__included{display:flex;gap:16px;align-items:center;border:2px solid var(--line);border-radius:16px;background:var(--soft);padding:18px 20px} .nznpd__qty{flex:0 0 auto;width:46px;height:46px;border-radius:12px;background:#FFF3E8;color:var(--o);font-weight:800;display:flex;align-items:center;justify-content:center} .nznpd__included strong{display:block;font-size:15px;margin-bottom:3px} .nznpd__uses{display:grid;grid-template-columns:repeat(2,1fr);gap:10px} .nznpd__use{padding:13px 14px;background:var(--soft);border-left:3px solid var(--o);border-radius:0 10px 10px 0;font-size:14px;color:var(--ink);line-height:1.4} .nznpd__faqs{display:grid;gap:10px} .nznpd__faq{border:2px solid var(--line);border-radius:12px;background:#fff;padding:0 16px;transition:border-color .18s ease} .nznpd__faq[open]{border-color:#FCE0C6} .nznpd__faq summary{list-style:none;cursor:pointer;padding:15px 0;font-weight:700;font-size:14px;color:var(--ink);display:flex;justify-content:space-between;align-items:center;gap:12px} .nznpd__faq summary::-webkit-details-marker{display:none} .nznpd__faq summary::after{content:\"\\203A\";flex:0 0 auto;color:var(--o);font-weight:800;font-size:20px;line-height:1;display:inline-block;transform:rotate(90deg);transition:transform .22s ease} .nznpd__faq[open] summary::after{transform:rotate(-90deg)} .nznpd__faq p{padding:0 0 16px;font-size:14px} .nznpd__faq[open] p{animation:nznpdReveal .24s ease} @keyframes nznpdReveal{from{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}} .nznpd p.nznpd__note{margin-top:16px;background:var(--soft);border:2px solid var(--line);border-radius:12px;padding:14px 16px;font-size:13.5px;color:var(--mut);line-height:1.55} @media (prefers-reduced-motion:reduce){.nznpd__faq summary::after{transition:none}.nznpd__faq[open] p{animation:none}} @media (max-width:749px){.nznpd__checks{grid-template-columns:1fr}.nznpd__uses{grid-template-columns:1fr}.nznpd__spec{grid-template-columns:1fr;gap:2px}}\u003c\/style\u003e\u003cdiv class=\"nznpd\"\u003e\n\u003cdiv class=\"nznpd__lead\"\u003e\n\u003cp class=\"nznpd__intro\"\u003eAdd accurate timekeeping to any project. The \u003cstrong\u003eDS1307 Tiny RTC\u003c\/strong\u003e module keeps real time — seconds through to year, with automatic leap-year handling — over a simple \u003cstrong\u003eI2C\u003c\/strong\u003e connection, and keeps ticking on its backup battery when main power is off. It also packs an onboard \u003cstrong\u003eAT24C32 EEPROM\u003c\/strong\u003e (4 KB) for non-volatile storage, plus a programmable square-wave output. Works with Arduino, ESP32, Raspberry Pi, PIC and most microcontrollers. Backup battery not included.\u003c\/p\u003e\n\u003cbr\u003e\u003cul class=\"nznpd__checks\"\u003e\n\u003cli\u003eDS1307 real-time clock over I2C\u003c\/li\u003e\n\u003cli\u003eOnboard AT24C32 32 Kbit (4 KB) EEPROM\u003c\/li\u003e\n\u003cli\u003eBattery-backed — keeps time when powered off\u003c\/li\u003e\n\u003cli\u003eProgrammable square-wave (SQ) output\u003c\/li\u003e\n\u003cli\u003e32.768 kHz crystal for accurate timekeeping\u003c\/li\u003e\n\u003cli\u003eWorks with Arduino, ESP32, Pi \u0026amp; PIC\u003c\/li\u003e\n\u003cli\u003eFootprint for an optional DS18B20 sensor\u003c\/li\u003e\n\u003cli\u003e5V operation, I2C clock address 0x68\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eSpecifications\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__specs\"\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eRTC chip\u003c\/span\u003e\u003cstrong\u003eDS1307 (I2C, address 0x68)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eEEPROM\u003c\/span\u003e\u003cstrong\u003eAT24C32, 32 Kbit \/ 4 KB (I2C, 0x50)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eInterface\u003c\/span\u003e\u003cstrong\u003eI2C (SCL, SDA)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eOperating voltage\u003c\/span\u003e\u003cstrong\u003e5V\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eCrystal\u003c\/span\u003e\u003cstrong\u003e32.768 kHz\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eBackup battery\u003c\/span\u003e\u003cstrong\u003eLIR2032 rechargeable (not included)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eOutput\u003c\/span\u003e\u003cstrong\u003eProgrammable square wave (SQ)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eExtras\u003c\/span\u003e\u003cstrong\u003eOnboard charge circuit · DS18B20 footprint\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eHeader pins\u003c\/span\u003e\u003cstrong\u003eSQ, DS, SCL, SDA, VCC, GND, BAT\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eDimensions\u003c\/span\u003e\u003cstrong\u003eapprox. 27 × 28 mm\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eWhat's in the box\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__included\"\u003e\n\u003cdiv class=\"nznpd__qty\"\u003e1×\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cstrong\u003eDS1307 Tiny RTC module\u003c\/strong\u003e\u003cp\u003eBackup battery (LIR2032) not included — see the note below on battery type.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eGreat for\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__uses\"\u003e\n\u003cdiv class=\"nznpd__use\"\u003eData loggers with timestamps\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eClocks, timers \u0026amp; alarms\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eScheduling lights, relays \u0026amp; automation\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eArduino \/ ESP32 \/ Raspberry Pi projects\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eStoring settings in the onboard EEPROM\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eLearning I2C and RTC basics\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003cdiv class=\"nznpd__qs\"\u003e\n\u003ch3\u003eGetting started\u003c\/h3\u003e\n\u003col class=\"nznpd__steps\"\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eWire it up\u003c\/strong\u003e\u003cp\u003eVCC→5V, GND→GND, SDA→SDA, SCL→SCL on your board.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eFit a battery\u003c\/strong\u003e\u003cp\u003eInsert a charged LIR2032 (rechargeable) so it keeps time when the power is off.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eAdd a library\u003c\/strong\u003e\u003cp\u003eUse an RTClib (DS1307) library in the Arduino IDE.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eSet the time\u003c\/strong\u003e\u003cp\u003eRun the set-time example once — it'll then keep time on its own.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eCommon questions\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__faqs\"\u003e\n\u003cdetails class=\"nznpd__faq\" open\u003e\u003csummary\u003eIs the battery included?\u003c\/summary\u003e\u003cp\u003eNo. The module takes a rechargeable LIR2032 coin cell (not included). The board has a built-in charging circuit to keep it topped up while powered.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eCan I use a normal CR2032 instead?\u003c\/summary\u003e\u003cp\u003eThe Tiny RTC is designed for a rechargeable LIR2032 and will try to charge whatever is fitted. If you want to use a non-rechargeable CR2032, disable the onboard charging circuit first (remove the charging resistor\/diode near the SQ pin) to avoid overcharging it. For most users a LIR2032 is the easy answer.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eDoes it work at 3.3V?\u003c\/summary\u003e\u003cp\u003eThe I2C lines work fine at 3.3V, but the onboard battery charging needs 5V. Power the module from 5V for normal use.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eWhat is the EEPROM for?\u003c\/summary\u003e\u003cp\u003eThe onboard AT24C32 gives you 4 KB of non-volatile storage (I2C address 0x50) for settings, logs or calibration — completely separate from the clock.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eWhich library should I use?\u003c\/summary\u003e\u003cp\u003eAdafruit RTClib (or similar) with the DS1307 class. Set the time once via the example sketch and it keeps running on the backup battery.\u003c\/p\u003e\u003c\/details\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cp class=\"nznpd__note\"\u003e\u003cstrong\u003eGood to know:\u003c\/strong\u003e takes a rechargeable LIR2032 (not included) — not a throwaway CR2032 unless you disable the charger. Every order is checked before it ships from our Te Awamutu stock.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"NZN Electronics","offers":[{"title":"Default Title","offer_id":42882511143008,"sku":"MOD-DS1307","price":3.49,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0664\/6127\/0112\/files\/DS1307ProductHero.png?v=1781746504","url":"https:\/\/www.nznelectronics.co.nz\/products\/ds1307-tiny-rtc-i2c-real-time-clock-module-at24c32-eeprom-arduino","provider":"NZN Electronics","version":"1.0","type":"link"}